According to the PR maestro Max Clifford, 'Nasty' Nick Bateman now has the world at his feet: an end-of-the-pier season as a panto villain, lucrative advertising contracts (presumably anything turned down by Vinnie Jones), spicy columns in the lad mags, months of Richard and Judy and the sofas of GMTV, modelling unattractive leather blousons for catalogues...

The trivial swill of modern media celebrity beckons, which is just as well because, having given up a career as an insurance underwriter to take his place in the Big Brother house, it doesn't look as though Nick's career game plan ever included a slow, stealthy crawl up through the ranks of corporate middle management.

In both his press conference (broadcast live on Sky) and his post-ejection interview with Davina McCall on Friday, Bateman appeared mightily vulnerable and confused. Was he, we wondered, hero or villain? Machiavellian genius or trembling fall-guy? Were those baby blues the eyes of a calculating sociopath or a pathetic naif? Were we seeing the 'real' Nick?

Even Nick didn't seem to know. 'If you live by the sword, you die by the sword,' he intoned. And: 'My strategy came into play before I entered the house. It was a gameshow.'

But there were flashes of humour too: was he, Davina wondered, a Channel 4 plant? 'No, Channel 5,' he retorted, lightning fast. No doubt about it, he's good at the game. He even talked about donating money to charity: 'Cancer research,' he said, eyes widening. 'I have a friend with cancer.' He wanted us to like him so much it hurt to watch.

He is said by Channel 4 insiders to be on an emotional rollercoaster right now, but I doubt he's ever been off it. 'I'm just an ordinary guy,' he claimed. No, you're not, Nick, you're a metaphor for media celebrity meltdown. To borrow Kirsty Young's catchphrase from the new ITV gameshow, The People Versus..., Nick is now the star of a show he's been preparing for all his life.

Bateman is said to be holed up in a luxury serviced flat somewhere in London, away from his family but attended by press officers and psychologists - the essential handmaidens for the narcissistic yet self-loathing modern media celebrity. He has also, fascinatingly, sold his soul to the Sun, the paper which campaigned for his eviction. Is it just that they offered the most money, or does Nick have a grasp of irony?

On Friday night, as Nichola was evicted from the Big Brother house, there were banners proclaiming 'Bring Back Nick', while the Nick Bateman Appreciation Society website features thousands of supportive emails. We are, one suspects, a mere mouse-click away from the Nick Bateman module in media studies courses.

Whatever Nick's fate, one thing is for sure: as far as Channel 4 is concerned Bateman is the best thing since Four Weddings and A Funeral: rivetingly exposed on Thursday night as a liar and a cheat, we now know he attracted an average of 5.5 million schadenfreude addicts - 63 per cent of the available TV audience and the channel's highest viewing figures since it screened Hugh Grant dithering at the altar in 1995.

Thursday night's revelations upped docusoap's emotional ante. It was the point where we moved away from the real life-as-light entertainment antics of Driving School, The Cruise or Airport, towards something potentially gladiatorial. When Darren shook his head in disbelief, muttering 'sick... sick' as the full extent of Nick's double-crossing was revealed around the communal table, the collective jangled nerve endings were exposed as never before. The men in general - and Craig in particular - took the betrayal the hardest and attempted to scramble up to the face-saving moral high ground (you've made me look a **** in front of everybody,' he said, pithily), while the girls just looked disappointed, wanted to get things straight: has he really done this to all of us? And I thought we had something special.

This was the point where everybody in the house, apart from Nick, fleetingly forgot they were contestants in a cheap game show, and so did we. It was the first sustained piece of emotional honesty the programme has produced. We tuned in in our millions as Nick carried on lying even when confronted with the hard evidence. How far would this man go to justify himself?

When he curled up on his bed, humiliated, could we be sure those weren't crocodile tears? And what was Mel doing there comforting him if she wasn't also indulging in a bit of advanced gameplaying herself?

Channel 4 pulled the plug after the tears and before we got to see if any blood was going to be shed. Very smart. Here, one felt, the bar was raised on what we - and the broadcasters - are coming to expect, demanding even, from voyeur TV. Real and extreme emotions in which Nick, a gameshow contestant after all, is stripped down and left emotionally naked. Was this pain or pleasure?

Big Brother is unarguably brilliant television. The production team have played with the viewers just as skilfully as Nick appeared to manipulate his co-habitees. Within hours of his ejection you could see the editorial focus shift straight on to Mel, the pretty, flirty Scary Spice-alike minx who is, in her own way, as masterful a manipulator as Bateman.

Watch her game plan closely during the next week, as the new competitor joins the show. My bet is that Big Brother will ensure she commands the majority of the edited screentime, even as she appears to play it cool.

But what about the bigger picture? What does the extraordinary success of Big Brother and its many worldwide versions say about us? To gain some perspective, I watched the Friday night show with a Big Brother virgin: 'This is horrible. Horrible. I hate this,' he said, but we remained glued because there's no doubt the show brings out the car crash voyeur in us all.

We might intend to slow down and drive past averting our eyes, but something always makes us turn and stare at the last minute.

None the less, there are signs that the 'reality' gameshow format may already be playing itself out. In September Channel 5 is bringing us Jailbreak, a three-week show with £100,000 at stake and 24-hour live coverage via the net. In Holland the show De Bus currently features 11 people sharing an 18-foot bed on the top deck of a bus. In a neat twist, contestants were invited to pay a £1,700 'fare' for the privilege - and the show still attracted 6,000 would-be passengers chasing the 24-hour live coverage on the net and a prize in the region of £270,000. 'Taking commercial television to an all-time low,' remarked one Dutch critic.

So how low can we go? In the US, CBS is broadcasting Survivor, a cross between Big Brother and Castaway, featuring 16 contestants stranded on an island in the South China seas. Undeterred by the fact that the original Swedish version of the show saw the island's first ejectee committing suicide, the programme's makers are currently pulling in audiences of up to 28 million to see contestants cooking rats ('you just skin them, gut them and put them on a stick. They were pretty good,' said basketball coach Gervase Patterson) and competing for $1 million.

And there's more in the pipeline: Chains of Love, an American format in which four men are 'shackled' to one woman (quite how this works has not been made clear) until she frees them one by one; Temptation, in which couples in long-term relationships are sent away to a resort with a 'dream date' in order to test their fidelity; and Glass House, in which... well, I think we can guess. It's a safe bet somebody is going to want to throw stones and, with any luck, it may well turn out to be the viewers.

It has been a cruel summer, a season of media witchhunts and the opportunistic exploitation of 'ordinary' people, of fake intimacy and kneejerk emotional outpourings: emotional porn. The empathetic coverage that accompanied the death of Sarah Payne turned swiftly to troublingly old-fashioned ret ribution; the casually curious, channel-hopping Big Brother viewers turn into a placard-waving mob. Perhaps, in a cynical society that doesn't quite know what to believe in anymore, where 'truth' so often comes loaded with spin, Reality TV is simply, inevitably, further blurring the boundaries between life and gameshow.

I'm nearly ready to avert my eyes from the pile-up. But not, I confess, until Big Brother ends its run.